The distributer told me they are approved for 46 lbs if you are using one or 100 lbs each if you are using both.
I think their actual attachment point is on the bottom frame rather than the skid, but I may be wrong there cos I haven't actually seen a set in the flesh.
Obviously that weight is part of your all up max weight so it is just redistributing what you are going to carry.
But then I do a lot of trips where: me plus son plus camping gear is below max weight but above the volume that is comfortable in the cabin.
But if the Vne is dropped I'm not that keen cos on our Secret Mens Business (see
http://secretmensbusiness.homestead.com )trips I'm trying to keep up with a squadron of fixed wingers who are TAS-ing about 100 - 105 kts. While I'm TAS-ing at 90 the separation is good but if it dropped me down to say 80 kts it starts making me too far behind.